Fabrication of functionally graded aerogels, cellular aerogels and anisotropic ceramics

We report on the fabrication and characterization of anisotropic porous materials: functionally graded, cellular and compositionally anisotropic aerogels and ceramics. This new class of materials was fabricated by photopolymerizing selected regions of a homogeneous monolith using visible light. Visible light is not significantly absorbed and not significantly scattered by organic molecules and oxide nanoparticles in wet gels and it allows fabrication of deeply penetrating, well-resolved patterns. Simple variations of the exposure geometry allowed fabrication of a wide variety of anisotropic materials without requiring layering or bonding.